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A057911 Numbers k such that 2*3^k + 5 is prime. 1
0, 1, 2, 3, 4, 5, 8, 9, 22, 23, 28, 37, 49, 53, 59, 74, 83, 149, 183, 577, 993, 1335, 1777, 7077, 8518, 8775, 12193, 20225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

a(29) > 20270. - Jinyuan Wang, Jan 20 2020

LINKS

Table of n, a(n) for n=1..28.

MATHEMATICA

Do[ If[ PrimeQ[ 2*3^n + 5 ], Print[ n ] ], {n, 0, 2500} ]

PROG

(PARI) is(n)=ispseudoprime(2*3^n+5) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A057910 (2*3^k - 5 is prime).

Sequence in context: A120430 A295033 A152606 * A085266 A280431 A056804

Adjacent sequences:  A057908 A057909 A057910 * A057912 A057913 A057914

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Nov 16 2000

EXTENSIONS

First term 0 inserted by Georg Fischer, Aug 01 2019

a(24)-a(28) from Jinyuan Wang, Jan 20 2020

STATUS

approved

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Last modified June 23 16:47 EDT 2021. Contains 345402 sequences. (Running on oeis4.)